1. Field of the Invention
The present invention relates to a device for energizing a load connected thereto for a predetermined time. In particular, the present invention relates to devices for actuating dump valves of a friction brake system upon the occurrence of wheel slide in order to correct the slide.
2. Description of the Prior Art
The prevention of wheel slide upon the application of a friction brake is an important safety consideration for many vehicles, particularly rapid transit vehicles. Existing circuits which perform this function utilize redundancy to lower the risk of failure; have complex, expensive circuitry; or utilize devices which have undesirable failure modes.
There is a need in the art for a simple, low-cost, reliable device for actuating the dump valve of a friction brake system to interrupt the braking action of a friction brake with no hazardous failure modes.